Center lane closure
Illinois typically uses Design Standards 701400 and 701446 to divert three lanes of traffic into one. If there is not a time of day when traffic volumes would allow a single lane open, the shoulder adjacent to the one open lane might be reconstructed to allow it to be used as a temporary second through-lane during center lane closure.
When workers are present, IDOT always requires one closed lane (or shoulder) adjacent to the closed work lane so that the construction crew has a safe lane to work in.
Topics: Lane Closure